| 摘要 |
A drill (10) comprises a drill body (14) and a removable tip (16). The drill body (14) has a main body portion (19), a thread (28), and a reduced diameter portion (33) between the main body portion (19) and the thread (28). The removable tip (16) has a main body portion and a thread (52) that is adapted to engage the thread (28) of the drill body (14). One of the threads is an internal thread (28) within a connection bore (22). The other thread is an external thread (52) extending from a shaft (44). The internal thread (28) is defined by a front face (30), a rear face (32), and a radial surface (34) extending between the front (30) and rear (32) faces. The external thread (52) is also defined by a front face (54), a rear face (56), and a radial surface (58) extending between the front (54) and rear (58) faces. The shaft (44) is adapted to be inserted in the connection bore (22) and rotated to engage the internal and external threads (28,52) with one another. <IMAGE> |
